Early mortality in acute myeloid leukemia with KMT2A rearrangement is associated with high risk of bleeding and disseminated intravascular coagulation

BACKGROUND

Acute myeloid leukemia (AML) with rearrangement of lysine methyltransferase 2a gene (KMT2Ar) is characterized by chemotherapy resistance and high rates of relapse. However, additional causes of treatment failure or early mortality have not been well-defined in this entity.

METHODS

In a retrospective analysis, causes and rates of early mortality following induction treatment were compared between a cohort of adults with KMT2Ar AML (N = 172) and an age-matched cohort of patients with normal karyotype AML (N = 522).

RESULTS

The 60-day mortality in patients with KMT2Ar AML was 15% compared with 7% with normal karyotype (p = .04). We found a significantly higher occurrence of major bleeding events (p = .005) and total bleeding events (p = .001) in KMT2Ar AML compared with diploid AML. Among evaluable patients with KMT2Ar AML, 93% exhibited overt disseminated intravascular coagulopathy compared with 54% of patients with a normal karyotype before death (p = .03). In a multivariate analysis, KMT2Ar and a monocytic phenotypic were the only independent predictors of any bleeding event in patients who died within 60 days (odds ratio, 3.5; 95% CI, 1.4-10.4; p = .03; odds ratio, 3.2; 95% CI, 1-1-9.4; p = .04, respectively).

CONCLUSION

In conclusion, early recognition and aggressive management of disseminated intravascular coagulopathy and coagulopathy are important considerations that could mitigate the risk of death during induction treatment in KMT2Ar AML.

PLAIN LANGUAGE SUMMARY

Acute myeloid leukemia (AML) with rearrangement of KMT2A is characterized by chemotherapy resistance and high rates of relapse. However, additional causes of treatment failure or early mortality have not been well-defined in this entity. In this article, that KMT2A-rearranged AML is demonstrably associated with higher early mortality and an increased risk of bleeding and coagulopathy, specifically, disseminated intravascular coagulation, compared with normal karyotype AML. These findings emphasize the importance of monitoring and mitigating coagulopathy in KMT2A-rearranged leukemia similar to what is done in acute promyelocytic leukemia.

Association between bariatric surgery and outcomes in chronic myeloid leukemia

BACKGROUND

Bariatric surgery is the most effective weight loss intervention. However, it can also decrease the bioavailability of oral medications. Tyrosine kinase inhibitors, the mainstay treatment for chronic myeloid leukemia (CML), are the most successful example of an oral targeted therapy. The impact of bariatric surgery on CML outcomes is unknown.

METHODS

In a retrospective analysis, we screened 652 patients with CML and identified 22 with prior bariatric surgery, and compared their outcomes to a matched cohort of 44 patients with no prior bariatric surgery.

RESULTS

The rate of early molecular response (3-month BCR::ABL1 < 10% International Scale) was lower in the bariatric surgery group compared with the control group (68% vs. 91%; p = .05), with longer median times to achieve complete cytogenetic (6 vs. 3 months; p = .001) or major molecular responses (12 vs. 6 months; p = .001). Bariatric surgery was associated with inferior event-free survival (5-year, 60% vs. 77%; p = .004) and failure-free survival (5-year, 32% vs. 63%; p < .0001). In a multivariate analysis, bariatric surgery was the only independent predictor for the risk of treatment failure (hazard ratio, 9.40; 95% CI, 2.71-32.55; p = .0004) or event-free survival (hazard ratio, 4.24; 95% CI, 1.67-12.23; p = .008).

CONCLUSIONS

Bariatric surgery is associated with suboptimal responses that require adapted treatment strategies.

A phase 1 study to evaluate the safety, pharmacology, and feasibility of continuous infusion nelarabine in patients with relapsed and/or refractory lymphoid malignancies

BACKGROUND

Nelarabine is a purine nucleoside analogue prodrug approved for the treatment of relapsed and refractory T-cell acute lymphoblastic leukemia (R/R T-ALL) and lymphoblastic lymphoma (T-LBL). Although effective in R/R T-ALL, significant neurotoxicity is dose-limiting and such neurotoxicity associated with nucleoside analogues can be related to dosing schedule.

METHODS

The authors conducted a phase 1 study to evaluate the pharmacokinetics and toxicity of nelarabine administered as a continuous infusion (CI) for 5 days (120 hours), rather than the standard, short-infusion approach.

RESULTS

Twenty-nine patients with R/R T-ALL/LBL or T-cell prolymphocytic leukemia (T-PLL) were treated, with escalating doses of nelarabine from 100 to 800 mg/m² /day × 5 days. The median age of the patients was 39 years (range, 14-77 years). The overall response rate was 31%, including 27% complete remission (CR) or CR with incomplete platelet recovery (CRp). Peripheral neuropathy was observed in 34% of patients, including four ≥grade 3 events related to nelarabine. Notably, there was no nelarabine-related central neurotoxicity on study. The maximum tolerated dose was not reached. Pharmacokinetic data suggested no relationship between dose of nelarabine and accumulation of active intracellular ara-GTP metabolite. Higher intracellular ara-GTP concentrations were statistically associated with a favorable clinical response.

CONCLUSION

Preliminary evaluation of continuous infusion schedule of nelarabine suggests that the safety profile is acceptable for this patient population, with clinical activity observed even at low doses and could broaden the use of nelarabine both as single agent and in combinations by potentially mitigating the risk of central nervous system toxicities.

A retrospective study of cladribine and low-dose cytarabine-based regimens for the treatment of chronic myelomonocytic leukemia and secondary acute myeloid leukemia

BACKGROUND

Patients with higher risk chronic myelomonocytic leukemia (CMML) have limited therapeutic options beyond hydroxyurea and hypomethylating agents (HMAs). Regimens based on a backbone of cladribine (CLAD), low-dose cytarabine (LDAC), and an HMA are effective low-intensity therapies for acute myeloid leukemia (AML).

METHODS

The authors conducted a retrospective chart review to evaluate the efficacy of CLAD/LDAC/HMA in CMML and secondary acute myeloid leukemia (sAML) arising from CMML. Responses were evaluated according to the 2006 International Working Group criteria for CMML and the 2017 European LeukemiaNet criteria for AML. The overall survival (OS), leukemia-free survival (LFS), and duration of response were evaluated with the Kaplan-Meier method. Patients were stratified on the basis of prior HMA exposure.

RESULTS

The authors identified 21 patients with CMML (eight with HMA-naive CMML and 13 with HMA-failure CMML) and 33 patients with sAML (11 with HMA-naive sAML and 22 with HMA-failure sAML) treated with CLAD/LDAC/HMA-based regimens. The CMML cohort was enriched for high-risk features (proliferative type, elevated blasts, and RAS/MAPK mutations). The overall response rate was 33% in CMML (50% in HMA-naive CMML and 23% in HMA-failure CMML) and 48% in sAML (82% in HMA-naive sAML and 32% in HMA-failure sAML). The median OS was 14.4, 8.8, 42.9, and 2.9 months for HMA-naive CMML, HMA-failure CMML, HMA-naive sAML, and HMA-failure sAML, respectively. The median LFS was 14.4 and 3.9 months for HMA-naive CMML and HMA-failure CMML, respectively.

CONCLUSIONS

CLAD/LDAC/HMA-based regimens are effective in a subset of patients with higher risk CMML and sAML arising from CMML who have not previously experienced HMA failure. These findings must be confirmed in prospective studies.

The emerging use of chemotherapy-free regimens in adults with Philadelphia chromosome-positive acute lymphoblastic leukemia

Before the development of tyrosine kinase inhibitors (TKIs), the outcome of patients with a diagnosis of Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia was dismal. Combinations of TKIs and chemotherapy improved survival rates, but allogeneic stem cell transplant was still relied on to avoid relapse in most cases. More recently, the chemotherapy-free combination of blinatumomab plus newer-generation TKIs has shown favorable results and may eliminate the need for allogeneic stem cell transplant. This review discusses the evolution of the treatment of Ph-positive acute lymphoblastic leukemia with chemotherapy-free regimens in the current era.

Integrated clinical genotype-phenotype characteristics of early T-cell precursor acute lymphoblastic leukemia

BACKGROUND

Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) is a distinct subtype of T-ALL with a unique immunophenotype and high treatment failure rate. The molecular genetic abnormalities and their prognostic impact in ETP-ALL patients are poorly understood.

METHODS

The authors performed systematic analyses of the clinicopathologic features with an emphasis on molecular genetic aspects of 32 patients with ETP-ALL.

RESULTS

The median age was 43 years (range, 16-71). The blasts were positive for cytoplasmic CD3 and CD7 and negative for CD1a and CD8. Other markers expressed included CD34 (88%), CD33 (72%), CD117 (68%), CD13 (58%), CD5 (partial, 56%), CD2 (38%), CD10 (25%), CD56 (partial, 19%), and CD4 (6%). Cytogenetic analyses revealed a diploid karyotype in 10 patients, simple (1-2) abnormalities in 10 patients, and complex karyotype in 10 patients. Next-generation sequencing for 21 patients demonstrated that all had gene mutations (median, four mutations per patient). The most frequently mutated genes were WT1 (38%), NOTCH1 (29%), NRAS (29%), PHF6 (25%), TP53 (24%), ASXL1 (19%), FLT3 (19%), and IKZF1 (19%). All patients except one received multi-agent chemotherapy, and 22 patients underwent allogeneic stem cell transplantation. Thrombocytopenia, an abnormal karyotype, and TP53 mutation were associated with markedly shortened overall survival. Stem cell transplantation significantly improved overall survival.

CONCLUSIONS

Patients with ETP-ALL often have high mutation burden with increased genomic instability. TP53 mutation was the only molecular prognostic marker and was associated with complex karyotype and greater than or equal to five mutations. These patients may benefit from stem cell transplantation, and recurrent gene mutations may be novel therapeutic markers.

Complex I inhibitor of oxidative phosphorylation in advanced solid tumors and acute myeloid leukemia: phase I trials

Although targeting oxidative phosphorylation (OXPHOS) is a rational anticancer strategy, clinical benefit with OXPHOS inhibitors has yet to be achieved. Here we advanced IACS-010759, a highly potent and selective small-molecule complex I inhibitor, into two dose-escalation phase I trials in patients with relapsed/refractory acute myeloid leukemia (NCT02882321, n = 17) and advanced solid tumors (NCT03291938, n = 23). The primary endpoints were safety, tolerability, maximum tolerated dose and recommended phase 2 dose (RP2D) of IACS-010759. The PK, PD, and preliminary antitumor activities of IACS-010759 in patients were also evaluated as secondary endpoints in both clinical trials. IACS-010759 had a narrow therapeutic index with emergent dose-limiting toxicities, including elevated blood lactate and neurotoxicity, which obstructed efforts to maintain target exposure. Consequently no RP2D was established, only modest target inhibition and limited antitumor activity were observed at tolerated doses, and both trials were discontinued. Reverse translational studies in mice demonstrated that IACS-010759 induced behavioral and physiological changes indicative of peripheral neuropathy, which were minimized with the coadministration of a histone deacetylase 6 inhibitor. Additional studies are needed to elucidate the association between OXPHOS inhibition and neurotoxicity, and caution is warranted in the continued development of complex I inhibitors as antitumor agents.

Implications of RAS mutational status in subsets of patients with newly diagnosed acute myeloid leukemia across therapy subtypes

Activating mutations in RAS have been reported in about 10-15% of patients with AML; previous studies have not identified a prognostic significance. However, RAS mutations have emerged as a potential resistance mechanism to treatment with inhibitors of FLT3, IDH, and BCL2. We aimed to determine the characteristics and outcomes of patients with RAS-mutated (RAS-mut) AML across therapy subsets of 1410 patients newly diagnosed (ND AML). RAS-mut was observed in 273 (20%) patients. Overall, patients with RAS-mut AML had an estimated 3-year survival rate of 38% vs. 28% in those with RAS wild type (RAS-wt), p = .01. Among patients with RAS-mut, favorable karyotype and concomitant NPM1 mutations were associated with a higher CR/CRi rate, OR 23.2 (95% CI: 2.7-192.7; p < .001) and OR 2.8 (95% CI: 1.1-6.9; p = .02), respectively, while secondary and treated secondary (ts)-AML were associated with low response rates, OR 0.34 (95% CI: 0.1-0.9; p = .04) and OR 0.22 (95% CI: 0.09-0.5; p = .001), respectively. Intensive chemotherapy was associated with high response rates OR 5.9 (95% CI: 2.9-12.2; p < .001). Better median OS was observed among those with favorable karyotype, HR 0.28 (95% CI: 0.1-0.6; p = .002), and those treated with intensive chemotherapy, HR 0.42 (95% CI: 0.2-0.6 p < .001). Conversely, ts- AML and co-occurrence of mutations in TP53 were associated with poor median OS; HR 2.3 (95% CI: 1.4-3.9; p = .001) and HR 1.7 (95% CI: 0.9-3.1; p = .06), respectively. The addition of venetoclax was associated with a non-significant improvement in CR/CRi and OS.

Retrospective comparison of survival and responses to Fludarabine, Cytarabine, GCSF (FLAG) in combination with gemtuzumab ozogamicin (GO) or Idarubicin (IDA) in patients with newly diagnosed core binding factor (CBF) acute myelogenous leukemia: MD Anderson experience in 174 patients

Fludarabine, cytarabine, GCSF (FLAG)-based induction/consolidation results in high remission rates in core binding factor (CBF) acute myelogenous leukemia. We treated 174 consecutive patients with newly diagnosed CBF-AML in a prospective clinical trial of FLAG-based induction/consolidation in combination with gemtuzumab ozogamicin (FLAG-GO; N = 65) or in combination with idarubicin (FLAG-IDA; N = 109). The 5 year RFS in the FLAG-GO cohort was significantly better than the FLAG-IDA cohort, 78% versus 59%, respectively (p-value = .02). In multivariate analysis for RFS, age (p = .0001), FLAG-GO regimen (p = .04), 4 log reduction in CBF-related fusion transcript by quantitative polymerase chain reaction (qPCR) in bone marrow samples at end of consolidation therapy (p = .03), and additional cytogenetic abnormalities (p = .03) were significant variables. Lower age (p = .0001) and 3 log or more transcript reduction at end of induction (p = .04) were significant variables predicting for better overall survival (OS), while there was strong trend for better OS with FLAG-GO (p = .06) regimen. FLAG-GO regimen was superior in optimal disease specific fusion transcript reduction at end of induction (p = .002), mid-consolidation (p < .01), and end of consolidation (p < .001) therapy. Induction/consolidation with FLAG-GO regimen results in better clinical outcomes in newly diagnosed patients with CBF-AML compared to FLAG-IDA and achieves deeper molecular clearance by qPCR assessment of the fusion transcripts.

International Consensus Classification of Myeloid Neoplasms and Acute Leukemias: integrating morphologic, clinical, and genomic data

The classification of myeloid neoplasms and acute leukemias was last updated in 2016 within a collaboration between the World Health Organization (WHO), the Society for Hematopathology, and the European Association for Haematopathology. This collaboration was primarily based on input from a clinical advisory committees (CACs) composed of pathologists, hematologists, oncologists, geneticists, and bioinformaticians from around the world. The recent advances in our understanding of the biology of hematologic malignancies, the experience with the use of the 2016 WHO classification in clinical practice, and the results of clinical trials have indicated the need for further revising and updating the classification. As a continuation of this CAC-based process, the authors, a group with expertise in the clinical, pathologic, and genetic aspects of these disorders, developed the International Consensus Classification (ICC) of myeloid neoplasms and acute leukemias. Using a multiparameter approach, the main objective of the consensus process was the definition of real disease entities, including the introduction of new entities and refined criteria for existing diagnostic categories, based on accumulated data. The ICC is aimed at facilitating diagnosis and prognostication of these neoplasms, improving treatment of affected patients, and allowing the design of innovative clinical trials.

Blinatumomab is associated with favorable outcomes in patients with B-cell lineage acute lymphoblastic leukemia and positive measurable residual disease at a threshold of 10-4 and higher

The presence of measurable residual disease (MRD) is the strongest predictor of relapse in acute lymphoblastic leukemia (ALL). We conducted a prospective, single-arm, phase II study in adults with B-cell ALL with MRD ≥1 × 10^-4 after ≥3 months from the start of frontline therapy or one month from any salvage therapy. Blinatumomab was administered at a standard dosing of 28 micrograms daily as a continuous infusion for up to five cycles and up to four additional maintenance cycles. Thirty-seven patients with a median age of 43 years (range, 22-84 years) were treated. Twenty-seven patients (73%) were treated in first complete remission (CR) and 10 patients (27%) in second CR and beyond. Eighteen patients (49%) had Philadelphia-chromosome positive ALL and received concomitant tyrosine kinase inhibitor therapy. Twenty-three patients (62%) had a baseline MRD ≥10^-3 . A median of three cycles (range, 1-9 cycles) were administered. Overall, 27 patients (73%) achieved MRD-negative remission. With a median follow-up of 31 months (range, 5-70 months), the estimated 3-year relapse-free survival (RFS) rate was 63% (95% confidence interval [CI], 43%-77%) and overall survival (OS) rate 67% (95% CI, 46%-81%). These rates were 51% (95% CI, 27%-70%) and 61% (95% CI, 36%-78%) in patients with baseline MRD ≥1 × 10^-3 , and 83% (95% CI, 45%-95%) and 77% (95% CI, 32%-95%) in patients with baseline MRD <10^-3 respectively. The rates of adverse events were consistent with previous studies of blinatumomab. In summary, blinatumomab induced MRD negativity in most patients and resulted in high rates of RFS and OS. This study is registered at www.clinicaltrials.gov as #NCT02458014. Funding was provided by Amgen Inc.

A Phase II Study of Azacitidine, Venetoclax and Trametinib in Relapsed or Refractory AML Harboring RAS Pathway-Activating Mutations

INTRODUCTION

RAS pathway mutations are common mechanisms of resistance to acute myeloid leukemia (AML) therapies. Trametinib, an oral MEK inhibitor, has been shown to have single-agent activity in relapsed/refractory AML and preclinical synergy with venetoclax.

METHODS

We conducted a single-center, open-label, phase 2 trial of the combination of azacitidine, venetoclax, and trametinib in patients with relapsed or refractory AML harboring a RAS pathway-activating mutation.

RESULTS

Sixteen patients were treated. The patients were heavily pretreated with a median number of 4 prior therapies; 13 (81%) had received prior hypomethylating agent (HMA) with venetoclax and 8 (50%) had undergone prior stem cell transplant. Four patients (25%) responded (CR, n=1; CRi, n=1; MLFS, n=2). Two of the 3 patients (67%) who had not previously received HMA plus venetoclax responded; in contrast, only 2 of the 13 patients (15%) who had previously received HMA plus venetoclax responded. The median OS was 2.4 months, and the 6-month OS rate was 31%. Related grade 3-4 adverse events occurred in 50% of patients, and 50% of patients required a dose adjustment of trametinib.

CONCLUSIONS

The combination of azacitidine, venetoclax and trametinib had only modest activity in patients with relapsed/refractory AML, with a response rate that was similar to previous reports of trametinib monotherapy. Substantial toxicity was observed with this combination. Given the established role of RAS pathway mutations in mediating resistance to AML therapies, future studies of better tolerated, more active inhibitors of this pathway are still needed.

Inhibition of mitochondrial complex I reverses NOTCH1-driven metabolic reprogramming in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is commonly driven by activating mutations in NOTCH1 that facilitate glutamine oxidation. Here we identify oxidative phosphorylation (OxPhos) as a critical pathway for leukemia cell survival and demonstrate a direct relationship between NOTCH1, elevated OxPhos gene expression, and acquired chemoresistance in pre-leukemic and leukemic models. Disrupting OxPhos with IACS-010759, an inhibitor of mitochondrial complex I, causes potent growth inhibition through induction of metabolic shut-down and redox imbalance in NOTCH1-mutated and less so in NOTCH1-wt T-ALL cells. Mechanistically, inhibition of OxPhos induces a metabolic reprogramming into glutaminolysis. We show that pharmacological blockade of OxPhos combined with inducible knock-down of glutaminase, the key glutamine enzyme, confers synthetic lethality in mice harboring NOTCH1-mutated T-ALL. We leverage on this synthetic lethal interaction to demonstrate that IACS-010759 in combination with chemotherapy containing L-asparaginase, an enzyme that uncovers the glutamine dependency of leukemic cells, causes reduced glutaminolysis and profound tumor reduction in pre-clinical models of human T-ALL. In summary, this metabolic dependency of T-ALL on OxPhos provides a rational therapeutic target.

Maximal activation of apoptosis signaling by co-targeting anti-apoptotic proteins in BH3 mimetic-resistant AML and AML stem cells

MCL-1 is known to play a major role in resistance to BCL-2 inhibition, but the contribution of other BCL-2 family proteins has not been fully explored. We here demonstrate ineffectiveness of MCL-1 inhibitor AMG176 in venetoclax-resistant, and conversely, of venetoclax in AMG176-resistant AML. Like cells with acquired resistance to venetoclax, cells with acquired resistance to AMG176 express increased MCL-1. Both cells with acquired resistance to venetoclax and to AMG176 express increased levels of BCL-2 and BCL-2A1, decreased BAX, and/or altered levels of other BCL-2 proteins. Co-targeting BCL-2 and MCL-1 was highly synergistic in AML cell lines with intrinsic or acquired resistance to BH3 mimetics or engineered to genetically-overexpress BCL-2 or BCL-2A1 or downregulate BAX. The combination effectively eliminated primary AML blasts and stem/progenitor cells resistant to or relapsed after venetoclax-based therapy irrespective of mutations and cytogenetic abnormalities. Venetoclax and AMG176 combination markedly suppressed anti-apoptotic BCL-2 proteins and AML stem/progenitor cells and dramatically extended mouse survival (median 336 vs control 126 d, P&lt;0.0001) in a PDX model developed from a venetoclax/hypomethylating agent therapy-resistant AML patient. However, decreased BAX levels in the bone marrow residual leukemia cells after 4-wk combination treatment may represent a resistance mechanism that contributed to their survival. Enhanced anti-leukemia activity was also observed in a PDX model of monocytic AML, known to be resistant to venetoclax therapy. Our results support co-dependence on multiple anti-apoptotic BCL-2 proteins and suppression of BAX as mechanisms of AML resistance to individual BH3 mimetics. Co-targeting of MCL-1 and BCL-2 eliminates otherwise apoptosis-resistant cells.

Clinical outcome of allogeneic stem cell transplantation in patients with B-cell lymphoid malignancies following treatment with targeted small molecule inhibitors

We aimed to study the risks of graft-versus-host disease (GVHD), non-relapse mortality (NRM) and survival outcomes of allogeneic stem cell transplantation (alloSCT) in patients with chronic lymphocytic leukemia (n = 17), Richter's syndrome (n = 14), or lymphoma (n = 18) after small molecule inhibitors (SMIs). Patients had a median of 4 prior therapies, including ibrutinib (n = 46; 94%), venetoclax (n = 19; 39%), and idelalisib (n = 6; 12%). Twenty-one (43%) had >1 SMI. P53 mutation was detected in 58% of patients. The 3-year overall and progression-free survival rates were 68% and 59%, respectively. The rates of grade II-IV and III-IV acute GVHD were 33% and 7%. The 1-year rates of chronic GVHD, NRM and relapse were 19%, 10% and 21%, respectively. Results were comparable to a historical control of patients who received alloSCT without a prior exposure to SMI. We conclude that a prior use of SMI does not impair the outcomes after alloSCT.

Management of acute lymphoblastic leukemia in older adults

Acute lymphoblastic leukemia, commonly known to affect the younger population, is a disease that is affecting the elderly in an increasing amount as the human life span continues to lengthen. Traditional cytotoxic agents are intolerable to elderly individuals owing to comorbidities, weakened immune systems, and organ dysfunction. Alternative agents and regimens are needed to allow for elderly patient to tolerate full cycles of therapy while providing complete and durable remissions. With the advent of targeted agents, such as monoclonal antibodies and bispecific T-cell engagers, a number of options have proven themselves to be effective in the elderly and optimal for tolerability. Here, we review and discuss the literature addressing regimens that use new agents, such as blinatumomab, inotuzumab ozogamicin, and venetoclax, and those that use modified dosing strategies of traditional chemotherapy.

The cure of leukemia through the optimist's prism

Progress is occurring at a dizzying rate across all leukemias. Since the authors' review of the topic in Cancer in 2018, numerous discoveries have been made that have improved the therapy and outcomes of several leukemia subsets. Hairy cell leukemia is potentially curable with a single course of cladribine followed by rituximab (10-year survival, ≥90%). Acute promyelocytic leukemia is curable at a rate of 80% to 90% with a nonchemotherapy regimen of all-trans retinoic acid and arsenic trioxide. The cure rate for core-binding factor acute myeloid leukemia (AML) is ≥75% with fludarabine, high-dose cytarabine, and gemtuzumab ozogamicin. Survival for patients with chronic myeloid leukemia is close to that for an age-matched normal population with BCR-ABL1 tyrosine kinase inhibitors (TKIs). Chronic lymphocytic leukemia, a previously incurable disease, may now be potentially curable with a finite duration of therapy with Bruton tyrosine kinase inhibitors and venetoclax. The estimated 5-year survival rate for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL) exceeds 70% with intensive chemotherapy and ponatinib, a third-generation BCR-ABL1 TKI, and more recent nonchemotherapy regimens using dasatinib or ponatinib with blinatumomab are producing outstanding results. Survival in both younger and older patients with ALL has improved with the addition of antibodies targeting CD20, CD19 (blinatumomab), and CD22 (inotuzumab) to chemotherapy. Several recent drug discoveries (venetoclax, FLT3 and IDH inhibitors, and oral hypomethylating agents) are also improving outcomes for younger and older patients with AML and for those with higher risk myelodysplastic syndrome.

Nine-Year Follow-up of Patients with Relapsed Follicular Lymphoma after Nonmyeloablative Allogeneic Stem Cell Transplant and Autologous Transplant

PURPOSE

To compare outcomes between patients with relapsed follicular lymphoma who received a nonmyeloablative allogeneic stem cell transplant (alloSCT) and those who received an autologous transplant (autoSCT).

PATIENTS AND METHODS

We evaluated 194 patients with follicular lymphoma who received an alloSCT (n = 98) or autoSCT (n = 96) at MD Anderson Cancer Center (Houston, TX). The transplant type used was based on donor availability and by Medicare reimbursement guidelines. Patients who received an alloSCT were enrolled in four consecutive trials in which they received fludarabine, cyclophosphamide (or bendamustine), and rituximab conditioning. autoSCT patients received R-BEAM (rituximab, carmustine, etoposide, cytarabine, and melphalan).

RESULTS

The median follow-up of survivors was 108 months for the alloSCT group and 102 months for the autoSCT group. Overall survival was significantly better for patients who received an alloSCT compared with those who received an autoSCT (62% vs. 46%; P = 0.048). Similarly, progression-free survival rates were 52% in patients who received an alloSCT and 31% in those who received an autoSCT (P < 0.001), and the 8-year relapse rates were 11% and 43%, respectively (P < 0.0001). Only three patients in the alloSCT group relapsed beyond 3.5 years. In the alloSCT group, the rates for grade 2 to 4 acute graft-versus-host disease (GVHD), grade 3 to 4 acute GVHD, and extensive chronic GVHD were 22%, 9%, and 38%, respectively. In the autoSCT group, the 8-year incidence of secondary myelodysplasia was 11%. Nonrelapse mortality was similar between the two groups (15% vs. 11% at 8 years; P = 0.27).

CONCLUSIONS

This study shows that alloSCT is curative and confers superior survival compared with autoSCT in patients with follicular lymphoma.

B-cell lymphoma/leukaemia 11B (BCL11B) expression status helps distinguish early T-cell precursor acute lymphoblastic leukaemia/lymphoma (ETP-ALL/LBL) from other subtypes of T-cell ALL/LBL

B-cell lymphoma/leukaemia 11B (BCL11B) is an essential transcription factor for T-cell lineage commitment and maturation. We investigated BCL11B expression by immunohistochemistry in T-lymphoblastic leukaemia/lymphoma (T-ALL/LBL) (n = 115). The majority (83%) of early T-cell precursor T-ALL/LBL (ETP-ALL) cases showed negative BCL11B expression, while most (84%) of non-ETP-ALL/LBL were positive for BCL11B. A simplified three-marker [BCL11B, cluster of differentiation 5 (CD5), CD13] immunophenotypic score discriminated reliably between ETP-ALL and non-ETP-ALL/LBL. In ETP-ALL, patients with positive BCL11B expression had a better overall survival than those with negative BCL11B (P = 0·009). In summary, BCL11B is a valuable marker for T-ALL/LBL subtyping and serves as a potential prognostic marker in patients with ETP-ALL.

A phase 2a, single-arm, open-label study of tafasitamab, a humanized, Fc-modified, anti-CD19 antibody, in patients with relapsed/refractory B-precursor cell acute lymphoblastic leukemia

Background

B‐precursor cell acute lymphoblastic leukemia (B‐ALL) in adults is an aggressive and challenging condition, and patients with relapsed/refractory (R/R) disease after allogeneic stem cell transplantation (SCT), or noncandidates for SCT, have a particularly poor prognosis. The authors investigated the activity of the Fc‐modified anti‐CD19 antibody tafasitamab in adults with R/R B‐ALL (NCT01685021).

Methods

Adults with R/R B‐ALL received single‐agent tafasitamab 12 mg/kg weekly for up to four 28‐day cycles. Patients with complete remission (with or without neutrophil/platelet recovery; complete remission [CR] or complete remission with incomplete count recovery [CRi]) after cycles 2, 3, or 4 could continue tafasitamab every 2 weeks for up to 3 further months. The primary end point was overall response rate (ORR).

Results

Twenty‐two patients were treated (median, 2 prior lines of therapy; range, 1‐8). Six patients completed 2 cycles, and 2 of these patients responded for an ORR of 9%; 16 patients (73%) progressed before their first response assessment. Responses lasted 8 and 4 weeks in the 2 patients with CR and minimal residual disease (MRD)–negative CRi, respectively. Tafasitamab produced rapid B‐cell/blast depletion in 21 of 22 patients within 1 to 2 weeks of first administration. Tafasitamab was well tolerated, with the most frequent adverse events being infusion‐related reactions (59.1%) and fatigue (40.9%). Grade 3 to 4 febrile neutropenia (22.7%) was the most common hematologic adverse event.

Conclusions

Tafasitamab monotherapy was associated with clinical activity in a subset of patients with R/R B‐ALL, including short‐lasting CR and MRD‐negative CRi. Given its favorable tolerability profile, further development of tafasitamab in chemoimmunotherapy combinations and MRD settings should be explored.

In patients with relapsed/refractory B‐precursor acute lymphoblastic leukemia, monotherapy treatment with the Fc‐modified anti‐CD19 antibody tafasitamab was associated with clinical activity, including short‐lasting complete remission and minimal residual disease (MRD)–negative complete remission with incomplete count recovery. In conjuntion with its favorable tolerability profile, further exploration of tafasitamab in chemoimmunotherapy combinations and MRD settings is warranted.

Ten-day decitabine with venetoclax versus intensive chemotherapy in relapsed or refractory acute myeloid leukemia: A propensity score-matched analysis

BACKGROUND

Relapsed/refractory (R/R) acute myeloid leukemia (AML) has poor outcomes. Although lower-intensity venetoclax-containing regimens are standard for older/unfit patients with newly diagnosed AML, it is unknown how such regimens compare with intensive chemotherapy (IC) for R/R AML.

METHODS

Outcomes of R/R AML treated with 10-day decitabine and venetoclax (DEC10-VEN) were compared with IC-based regimens including idarubicin with cytarabine, with or without cladribine, clofarabine, or fludarabine, with or without additional agents. Propensity scores derived from patient baseline characteristics were used to match DEC10-VEN and IC patients to minimize bias.

RESULTS

Sixty-five patients in the DEC10-VEN cohort were matched to 130 IC recipients. The median ages for the DEC10-VEN and IC groups were 64 and 58 years, respectively, and baseline characteristics were balanced between the 2 cohorts. DEC10-VEN conferred significantly higher responses compared with IC including higher overall response rate (60% vs 36%; odds ratio [OR], 3.28; P < .001), complete remission with incomplete hematologic recovery (CRi, 19% vs 6%; OR, 3.56; P = .012), minimal residual disease negativity by flow cytometry (28% vs 13%; OR, 2.48; P = .017), and lower rates of refractory disease. DEC10-VEN led to significantly longer median event-free survival compared with IC (5.7 vs 1.5 months; hazard ratio [HR], 0.46; 95% CI, 0.30-0.70; P < .001), as well as median overall survival (OS; 6.8 vs 4.7 months; HR, 0.56; 95% CI, 0.37-0.86; P = .008). DEC10-VEN was independently associated with improved OS compared with IC in multivariate analysis. Exploratory analysis for OS in 27 subgroups showed that DEC10-VEN was comparable with IC as salvage therapy for R/R AML.

CONCLUSION

DEC10-VEN represents an appropriate salvage therapy and may offer better responses and survival compared with IC in adults with R/R AML.

A phase I/II study of the combination of quizartinib with azacitidine or low-dose cytarabine for the treatment of patients with acute myeloid leukemia and myelodysplastic syndrome

The FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) mutation in acute myeloid leukemia (AML) is associated with poor prognosis. We hypothesized that quizartinib, a selective and potent FLT3 inhibitor, with azacitidine (AZA) or low-dose cytarabine (LDAC) might improve the outcomes in patients with FLT3-ITD-mutated AML. In this open-label phase I/II trial, patients of any age receiving first-salvage treatment for FLT3-ITD AML or age >60 years with untreated myelodysplastic syndrome or AML were treated with quizartinib plus AZA or LDAC. Seventy-three patients were treated (34 frontline, 39 first salvage). With regard to previously untreated patients, the composite response (CRc) rate was 87% (n=13/15: 8 complete responses [CR], 4 CR with incomplete hematologic recovery [CRi], 1 CR without platelet recovery [CRp]) among the patients treated with quizartinib/AZA and 74% (n=14/19: 1 CR, 8 CRi, 5 CRp) among those treated with quizartinib/LDAC. The median overall survival was 19.2 months for the cohort treated with quizartinib/AZA cohort and 8.5 months for the patients treated with quizartinib/LDAC; the corresponding relapse-free survival figures were 10.5 and 6.4 months, respectively. With regard to previously treated patients, the CRc rate was 64% (n=16/25 in the quizartinib/AZA cohort and 29% (n=4/14)) in the quizartinib/LDAC cohort. The median overall survival for patients treated with quizartinib/AZA and quizartinib/LDAC was 12.8 versus 4 months, respectively. QTc prolongation grade 3 occurred in only one patient in each cohort. Quizartinib-based combinations, particularly with AZA, appear effective in both frontline and first salvage therapy for patients with FLT3-ITD-mutated AML and are well tolerated. ClinicalTrials.gov identifier: NCT01892371.

Hyper-CVAD plus ofatumumab versus hyper-CVAD plus rituximab as frontline therapy in adults with Philadelphia chromosome-negative acute lymphoblastic leukemia: A propensity score analysis

BACKGROUND

The outcome of hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone plus ofatumumab hyper-CVAD + ofatumumab (hyper-CVAD + ofatumumab) has not been compared with the outcome of hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone plus ofatumumab hyper-CVAD plus rituximab (hyper-CVAD + Rituximab) in Philadelphia chromosome-negative acute lymphoblastic leukemia (ALL) in a randomized clinical trial.

METHODS

The authors compared the outcomes of 69 patients treated with hyper-CVAD + ofatumumab and 95 historical-control patients treated with hyper-CVAD + Rituximab. Historical-control patients were treated with hyper-CVAD + Rituximab if they had CD20 expression ≥ 20%. Ofatumumab (day 1 of course 1, 300 mg intravenously; subsequent doses, 2000 mg intravenously) was administered on days 1 and 11 of courses 1 and 3 and on days 1 and 8 of courses 2 and 4 for a total of 8 doses. A propensity score analysis with inverse probability of treatment weighting (IPTW) was performed to adjust for baseline covariates between groups.

RESULTS

The median event-free survival with stem cell transplantation (SCT) censoring was 33 and 65 months with hyper-CVAD + Rituximab and hyper-CVAD + ofatumumab, respectively (crude P = .064; IPTW P = .054). The median overall survival with SCT censoring was 52 months and not reached, respectively (crude P = .087; IPTW P = .097).

CONCLUSIONS

Hyper-CVAD + ofatumumab was associated with better outcomes than hyper-CVAD + Rituximab among patients with newly diagnosed Philadelphia chromosome-negative ALL.

Impact of luteinizing hormone suppression on hematopoietic recovery after intensive chemotherapy in patients with leukemia

Treatment of acute leukemia with intensive chemotherapy leads to an increased risk of myelosuppression. Luteinizing hormone (LH) blockade improves hematopoietic recovery in mice after radiation or chemotherapy, through protection of the hematopoietic stem cells which express the LH receptor. We hypothesized that LH blockade improves hematopoietic recovery following intensive chemotherapy in patients with leukemia. We conducted a retrospective analysis on pre-menopausal women with acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) who received intensive chemotherapy and leuprolide given for abnormal uterine bleeding prevention or treatment. Given that leuprolide is more commonly administered in younger patients, we performed propensity score matching between the leuprolide (AML n=64; ALL n=49) and control groups (AML n=128; ALL n=98 patients). Patients with AML who received leuprolide had an additional increase of 13.8x10⁹/L/year in their platelet count, and a 0.19x 10⁹/L/year increase in their lymphocyte count after chemotherapy compared to control (P=0.02; P=0.03 respectively). Those with ALL who received leuprolide had an additional increase of 0.37x10⁹/L/year in their absolute neutrophil count (P=0.02). In AML, leuprolide was associated with higher long-term hemoglobin levels (P<0.001) and less blood transfusions (mean, 23.9 vs. 34.7 units; P=0.002) compared to control. In a multivariate analysis, leuprolide was identified as an independent factor predicting improved hemoglobin levels, lymphocyte and platelet counts in AML. In conclusion, leuprolide use in leukemia patients receiving intensive chemotherapy was associated with improved long-term blood count recovery and with decreased transfusion requirements in AML.